Opening up the Window (more hope for stroke victims)

Susan C. Fagan, Pharm.D., BCPS, FCCP
November, 2008

The European Cooperative Acute Stroke Study (ECASS) investigators have provided the best news in more than a decade regarding the treatment of acute ischemic stroke in their most recent report in the New England Journal of Medicine.¹

Since intravenous tissue plasminogen activator (tPA) was shown to be effective in reducing disability due to acute ischemic stroke,² the widespread use of this therapy has been limited by the very short time window of 3 hours from the onset of symptoms. Now, with the results of the ECASS III, carefully selected patients (patients with severe stroke were excluded) treated with tPA between 3 and 4.5 hours (median of 3.9 hours) after the onset of symptoms were 7.2 % (absolute improvement) more likely to experience a minimal or no disability at 90 days. This is similar to that expected when patients are treated within 3 hours.

The main fear of treating patients outside the 3 hour window has been the potential to increase the risk of symptomatic intracerebral hemorrhage. In this study, the risk was significantly increased in the tPA-treated group, but not at rates that outweighed the benefit. Patients treated with tPA had a 2.4% rate of symptomatic hemorrhage compared to 0.2% in the placebo-treated patients. These rates are lower than that reported in the original NINDS tPA study (6.4% vs. 0.6%).2 The ECASS investigators also presented data, using the more conservative NINDS definition of symptomatic ICH, where the rates were 7.9% with tPA and 3.5% with placebo.

This paper is important in that it will probably lead to more acute stroke patients receiving intravenous tPA which will result in less disability due to stroke.

References

• Hacke W, Kaste M, Bluhmki E et al. N Engl J Med 2008;359:1317-1329.
  
  
• The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. Tissue plasminogen activator for acute ischemic stroke. N Engl J Med 1995;333:1581-1587.